The invention relates to clamping devices for fixing a bar so as to be substantially without play.
Clamping devices are known which comprise separate clamping jaws arranged in the housing of a clamping device, the jaws being displaceable between a release position and a locked position along guide faces inclined towards the central axis of the bar by means of a servo-piston which moves parallel to the bar. Such a device is described in German Patent Application No. P 31 18 449.9. In this arrangement, an annular piston associated with the servo-drive displaces the clamping jaws radially onto associated inclined guide faces in the housing to firmly clamp the load-carrying bar in a self-locking manner. The locking action is cancelled by a movement of the servo-piston in the release direction.
For many purposes, a clamping device of this kind enables a satisfactory non-variable clamping action to be provided in the setting position reached, and this action can be cancelled without movement of the load in the direction for release. However, for some applications, for example in the precise adjustment and setting of heavy machine parts, including the setting of the rollers in trains of rollers and also in the precise adjustment of the level of structural components, a clamping device is required that gives a yielding engagement and prevents any appreciable changes in the setting position.